Major heating issue please help..

[john cockshott]

I have an open vented heating system and the boiler is a Veissman open vent condenser boiler 100w

 

[skywatch99]

You could try closing all the rad valves on the ground floor and see then if the hot water gets upstairs. I assume all valves on the upstairs rads are open?
Are the upstairs rads cold at the top and bottom?

 

[Daveydub]

Turn all radiators on. Run heating and turn off any rads that are getting hot. This will force circulation to other rads so continue untill last radiator gets hot. Now re-open all rads. If you have TRVs fitted to any non-working rads , remove trv head & check that pin is moving freely ie. not stuck in closed position.

 

[xr4x4]

Turn all radiators on. Run heating and turn off any rads that are getting hot. This will force circulation to other rads so continue untill last radiator gets hot. Now re-open all rads. If you have TRVs fitted to any non-working rads , remove trv head & check that pin is moving freely ie. not stuck in closed position.

I agree with this...

How can the system have been correctly balanced if half the rads aren't working...?!

 

[john cockshott]

Hi I have done this numerous times but its not worked

 

[xr4x4]

Hi I have done this numerous times but its not worked

So what happens when you do this?

 

[john cockshott]

i turn off the hot ones upstairs and they go cold and still nothing happens down stairs the rads are still cold. The boiler continues to increase temp quickly and stop at 60 degrees and immediately cool down to 27 degrees in 1 minute..then it starts up again and on we go..

 

[Daveydub]

"The boiler continues to increase temp quickly and stop at 60 degrees and immediately cool down to 27 degrees in 1 minute..then it starts up again and on we go.."

So...... The boiler is still dumping heat somewhere therefore circulating somewhere. Did you do this on heating only or heating and hot water? Repeat on heating only. Any TRVs?

 

[xr4x4]

I'm no boiler expert but I'm sure the boiler should kick in before 27o.

Anyway... You must have a blockage...next step is to take a cold rad off and see of you can get a flow from the valves.

 

[Daveydub]

If boiler is dropping from 60 to 27 in 1 minute then the pump is still circulating water somewhere. Rad in airing cupboard that you have forgotten about? Hot water circuit?
We may then have to talk about bypasses but a bypass would not be dissipating heat this quickly so 1 step at a time.
What you are looking to do is use the full power of the pump to drive any air out of pipework so every working circuit closed.

 

[simond]

This boiler can get easily get blocked HEX, long path narrow waterway. The electronics build in delays restarting confusing the diagnosis.

Easy enough to blow it out.